1. Field of the Invention
This invention relates to an interior illumination lamp for a vehicle which is mounted within a room of the vehicle.
2. Related Art
Generally, a vehicle has an interior illumination lamp mounted on a ceiling thereof. As shown in FIG. 15, one known such interior illumination lamp includes a function portion 4 which is fixed to a ceiling 1 of a vehicle body, and is partially exposed through an opening 3 formed through a ceiling plate (interior member) 2, and a design portion (cover lens) 5 which is fitted into the opening 3 in the ceiling plate 2 from the inside of a vehicle room, and is attached to the function portion 4 (see, for example, Unexamined Japanese Patent Publication 2002-79879).
This interior illumination lamp includes a switch 6 provided at the function portion 4, and a slidable switch knob 7 provided at the design portion 5. When the design portion 5 is to be attached to the function portion 4, a slider 8 of the switch 6 is engaged in an engagement portion 9 (in the form of a recess) formed in the switch knob 7 as shown in FIG. 16, and by doing so, the switch 6 can be operated by sliding the switch knob 7.
In the interior illumination lamp of the above construction, if the slider 8 of the switch 6 is disposed out of registry with the engagement portion 9 of the switch knob 7 at the time of attaching the design portion 5 to the function portion 4, the slider 8 can not be engaged in the engagement portion 9, and interferes with other portion than the recess of the engagement portion 9, so that the lamp can not be smoothly assembled.
Therefore, it is necessary that the slider 8 of the switch 6 and the engagement portion 9 of the switch knob 7 should be disposed accurately in registry with each other at the time of attaching the design portion 5 to the function portion 4, and therefore the assembling operation has been cumbersome.